Surfacing apparatus



Oct. 14, 1930. H, R, STRATFQRD 1,778,471

' SURFACING APPARATUS Filed Nov. 16. 1928 Patented ct. 14, 1930 UNITED STATES PATENT OFFICE vHITRBERII? R. STRATFORD, 0F CLEVELAND, OHIO, ASSIGNOR TO THE STRATIORE COMPANY, OF CLEVELAND, OHIO, A CORPORATION OP' OHIO SURFACING APPARATUS Application led November 16, 1928. Serial No. 319,822.

The present invention, relating, as indicated, to surfacing apparatus is more particularly directed to an improved supporting pad for use in surfacing apparatus of the type now so commonly used for grinding, polishing, buiiing and similarly treating surfaces such as panels of wood, metal and other material, and such articles such as castings, automobile bodies, fenders, hoods and the like. The apparatus commonly employed for this purpose consists of a frame or casing provided with handles for an operator and with a projecting shaft, on the end of which is mounted a supporting pad, against which is removably secured a surfacing disk, usually constructed of abrasive adhesively secured to a suitable backing of paper, cloth or some combination of the two. The shaft on which the pad and disk are carried is operated through gearing journaled in the frame or casing and then by a flexible shaft extending to a suitable source of power, althou h in many cases the operating shaft whic carries the ad and disk are operated directly from a se f-contained air or electric motor mounted in the frame or casing.

The present invention is directed to a new and improved pad to be used in machines of the above construction and for the purposes, some of which are referred to above. The principal object of the invention is the provision of a simple and inexpensive pad for the purpose described and one which has a more universal application and usefulness than the more specialized and expensive pads which have heretofore been employed, but which have been better adapted to some individual type of surfacing operation than to general operations involving a considerable range of operations.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims; the annexed drawing and the following de- 2 is a side elevation showing the apparatus n of Fig. 1 in operation against a convex surface.

In Fig. 1 I have shown a surfacing apparatus consisting of a frame or casing 1 provided with annularly related handles 2 and 3, of which the handle 8 is hollow and is adapted to receive therein a flexible shaft (not shown) for the operation of suitable connecting gears (not shown) mounted in a casing 1 and adapted to operate a shaft 4 exn tending from the lower side of the casing. The shaft 4 is adapted to removably receive my improved supporting pad, which will now be described.

My improved pad consists of a circular supportinv disk 10 of some tough, resistant, but semiexible material, such for example, as rubber cured to a consistency permitting it to flex under severe lateral pressure, but of suiiicient rigidit to allow it to be used with relatively litt-le exibility against flat or convex surfaces. This rubber pad 10,is preferably reinforced by means of one or more layers of some tough fabric 11 embedded in the rearward portion of the pad 10 and extendin substantially throughout the area thereo It is further supported by means of a central reinforcing section 12, which may be formed of a hard relatively inflexible material, such as hard rubber vulcanized to the forward section 10 of the pad, thus making the forward and rear sections of the pad integral with each other.

The supporting portion 12 of the pad issecured to a hub member 13 internally threaded, adapting it to be removably engaged over the threaded lower end 14 of the shaft 5. The lower portion of the pad 10 is recessed, adapting it -to receive an abrasive disk 15 which is held in operative position by means of a locking plate 16 which forces the abrasive disk into the recesses in the pad and is itself engaged with the threaded hollow end ofthe shaft 14.

The action of the present pad against concave surfaces is shown in Fig. 2. When aplied to such a surface with considerable ateral pressure the pad is of a consistency to permit it to be flexed or distorted out of its normal plane, allowing it to adapt itself to the curvature of the surfaces to be operated upon. but at the same time there is sufficient resistance to such flexure in the pad to allow the pad to operate both on this type of surface and on relatively flat and convex surfaces. In the latter operation only ordinary pressure is re uired, due to the resistance of the pad to exure. Y

In a ad of the character described intended or a number of different operations and for use against different types of surfaces it is essential that the pad operate in 4as nearly as possible the same manner as relatively stiffpads when used on fiat surfaces. If this action is not secured then the pad, even on fiat surfaces, has to be applied p to the work with considerable pressure to produce the desired cutting action, causing a considerable flexing and a resultant severe wear on theV abrasive disk tending both to break the backing of the disk and to loosen the grain of abrasive therefrom. The present pad is well adapted to the varied service for which it is intended. It has suficient rigidity to operate on flat surfaces without the use of any considerable pressure and is `still sufficiently flexible to follow surfaces vof but relatively soft rubber provided with anl exposed relatively flat work-en aging surface and with a layer of rein orcing matgrial adjacent its other fiat surface and having a supporting disk of smaller diameter concentrically disposed against said 'lastnamed surface and integrally united thereto.

2. A supporting pad of the character described comprising a circular disk of toughV HERBERT R. STRATFORD. 

